Automatic control system for storage systems transfer cart

ABSTRACT

An automatic control system is disclosed for a transfer cart in a storage system in which the transfer cart moves a stacker vehicle from aisle to aisle for transferring material-units to and from bins in a selected aisle. The transfer cart is provided with aisle selector means and the bin structure is provided with aisle signal means at each aisle. Signal responsive means on the transfer cart is selectively responsive to the aisle signal means and controls the motive power means for the transfer cart. The transfer cart moves initially at a relatively high speed until it reaches the selected aisle and then the speed is reduced to approach the final position at which position responsive means causes actuation of locking means to hold the transfer cart in a fixed position relative to the bin structure with the transfer cart locked in alignment with the selected aisle. The stacker vehicle may be operated between the vehicle station on the transfer cart and the assigned bin. The control system is provided with interlocks so that the transfer cart cannot be moved unless the stacker vehicle is aboard and the locking means are released. Additionally, the control system includes aisle selector switches which are interconnected so that the aisle selection cannot be changed while the transfer cart is in motion and to disable the motive power means unless one of the selector switches is actuated. The transfer cart is driven by a reversible servo motor energizable at selected speeds in accordance with the control signals applied to a servo amplifier. The control signals are dependent upon the actuation of the selector switches and the signal responsive means as the selected aisle is approached.

Ute States Burch et al.

atent [191 AUTOMATIC CONTROL SYSTEM FOR STORAGE SYSTEMS TRANSFER CART Inventors: Arthur R. Burch, Plainwell; Charles E. Bates, Battle Creek, both of Mich.

[73] Assignee: Clark Equipment Company,

Buchanan, Mich.

[*1 Notice: The portion of the term of this patent subsequent to Oct. 27, 1987, has been disclaimed 22 Filed: July 23, 1970 21 Appl. No.: 57,745

Related US. Application Data Primary ExaminerGerald M. Forlenza Assistant ExaminerR. B. Johnson Att0rney-Kenneth C. Witt, John C. Wiessler, Robert H. Johnson and Lewis J. Lamm M4 TE R/A L UNI T RETRA g 9oa v 900 LATERA i" PLATFORM 511v STRUCTURE TRANSFER CART a (EXTENDED) STACKER [4 1 *July 17, 1973 [57] ABSTRACT An automatic control system is disclosed for a transfer cart in a storage system in which the transfer cart moves a stacker vehicle from aisle to aisle for transfer ring material-units to and from bins in a selected aisle. The transfer cart is provided with aisle selector means and the bin structure is provided with aisle signal means at each'aisle. Signal responsive means on the transfer cart' is selectively responsive to the aisle signal means and controls the motive power means for the transfer cart. The transfer cart moves initially at a relatively high speed until it reaches the selected aisle and then the speed is reduced to approach the final position at which position responsive means causes actuation of locking means to hold the transfer cart in a fixed position relative to the bin structure with the transfer cart locked in alignment with the selected aisle. The stacker vehicle may be operated between the vehicle station on the transfer cart and the assigned bin. The control system is provided with interlocks so that the transfer cart cannot be moved unless the stacker vehicle is aboard and the locking means are released. Additionally, the control system includes aisle selector switches which are interconnected so that the aisle selection cannot be changed while the transfer cart is in motion and to disable the motive power means unless one of the selector switches is actuated. The transfer cart is driven by a reversible servo motor energizable at selected speeds in accordance with the control signals applied to a servo amplifier. The control signals are dependent upon the actuation of the selector switches and the signal responsive means as the selected aisle is approached.

26 Claims, 38 Drawing Figures MATERIAL if} aw AREA am/s REMOVED} AISLE N0 2 Patented July 17, 1973 3,746,189

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51 Sheets-Shoot 7 TRANSFER CART DIRECTION OF TRAVEL AISLE NUMBERS 830 R58 RS3 w o- RS9 RS4 RSIO W RS5 N (6134 RS u N RS 6 N SHOWN AT AISLE NO.I

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51 Sheets-Shoot 13 l N VEN T0125 ARTHUR R. BURCH F/ I] CHARLES E BATES 6 9/5 g ATTORNE Y8 Patented RSZB-IO RSZB-OO RSZB-l RSZB-O July 17, 1973 3,746,189

31 Sheets-Shoot 14 INVENTORS' ARTHUR H. Bum/1 CHARLES E. Bares ATTORNEYS Patented July 17, 1973 3,746,189

(51 Sheets-Sh 16 FIG /5 Patented July 17, 1973 151 Sheets-Shoot 17 S wmm mm] 5 W E WS HE. TL RR m QM ATTORNEYS Patented July 17, 1973 3,746,189

151 Sheets-Shoot l 8 INVENTORS Ann/w? I; BURCH, CHARLES- E 84723 ATTORNEYS Patented July 17, 1973 3,746,189

51 Sheets-Shoot l9 INVENTORS ARTHUR R. BURCH,

CHARLES E BATES 

1. An automatic storage system for material-units comprising a bin structure including plural sets of bins arranged in rows with aisles therebetween, a stacker vehicle including drive means movable forward and backward within an aisle and including means for transferring a material-unit between the stacker vehicle and an assigned bin, a transfer cart including a vehicle station thereon adapted to receive the stacker vehicle, said transfer cart being movable forward and backward across the ends of said aisles, motive power means for said transfer cart including a servo motor, control means including a servo amplifier connected with said servo motor, said servo motor being reversible and operable at relatively high speed when a first control signal is applied to said servo amplifier and operable at a relatively low speed when a second control signal is applied to said servo amplifier, aisle signal means at each of said aisles, aisle selector means including a plurality of selector switches corresponding to each different aisle and adapted to be actuated to select the aisle in which the assigned bin is located, the actuation of any of said selector switches being effective to apply a said first control signal to said servo amplifier, direction control means connected with said selector switches and adapted to respond to the order in which said switches are operated to determine the direction of rotation of said servo motor, signal responsive means on said cart connected with said selector means and being selectively responsive to the aisle signal means to produce said second control signal when the selected aisle is reached to reduce the speed of said servo motor permanent magnet means adjacent said aisle and switching means on said tranfer cart responsive to said permanent magnet means and adapted to produce a third control signal when it reaches a predetermined position relative to said aisle, locking means for said transfer cart, actuating means for said locking means connected to said switching means and responsive to the third control signal for locking said transfer cart in fixed position relative to said bin structure at a selected aisle.
 2. The invention as defined in claim 1 and further including interlock means connected with the aisle selector means and responsive respectively to the presence and absence of the stacker vehicle at the vehicle station on the transfer cart for enabling and disabling energization of the motive power means.
 3. The invention as defined in claim 1 and further including holding means connected with said selector switches and adapted to prevent a change in actuation of said selector switches while said servo motor is energized.
 4. The invention as defined in claim 1 wherein said aisle selector means includes a transfer control switch movable between a first position and a second position, said transfer control switch being effective in said first position to energize said actuating means to release said locking means and effective in said second positon to apply said first control signal to said servo amplifier, and interlock means connected to said transfer control switch and said locking means to prevent energization of said servo motor unless said locking means are in the released position.
 5. The invention as defined in claim 4 wherein said interlock means includes position responsive switch means connected for actuation by said locking means and electrically connected with said transfer control switch to disable the control switch from energizing said servo motor unless said locking means are in the released position.
 6. The invention as defined in claim 1 and further including means connected with all of said aisle selector switches and adapted to prevent energization of said servo motor when none of the selector switches is actuated.
 7. An automatic storage system for material-units comprising: a storage structure with multiple bins arranged in rows and columns and defining an aisle adjacent said bins, each of said bins being adapted to receive a material-unit, a transfer cart adapted to move forward and backward across the end of said aisle, a stacker vehicle adapted to moVe foward and backward in said aisle between said transfer cart and a selected bin, said stacker vehicle including a platform adapted to support a material-unit and to move laterally of said aisle to transfer a material-unit to or from a selected bin, a said transfer cart including a vehicle station located thereon adapted to receive the stacker vehicle and a load station located thereon so positioned as to permit said stacker vehicle platform to move laterally to transfer a material unit to and from said load station, said stacker vehicle including driving means for moving it along said aisle and for actuating said platform, control means for said driving means and adapted to selectively position said vehicle with said platform in accurate alignment with a selected bin or with said load station whereby a material-unit may be transferred between the load station and the selected bin, positioning means disposed on said load station adapted to engage a material-unit thereon for positioning it along two axes into accurate alignment with said load station and thereby with said platform, whereby material-units deposited on the load station are properly oriented by the positioning means for transfer into a selected one of said bins.
 8. The invention as defined in claim 7 wherein said load station includes means responsive to the presence of a material-unit on said load station for energizing said positioning means.
 9. The invention as defined in claim 7 wherein said load station comprises a pallet dolly movable from a retracted position at the load station to an extended position adjacent the load station, said pallet dolly being adapted to receive a material-unit while it is in the extended position and means responsive to the presence of said pallet dolly in the retracted position for energizing said positioning means.
 10. The invention as defined in claim 9 including power means connected with said pallet dolly for moving it between said extended position and said retracted position, and pallet dolly control means connected with said power means and being responsive to a manual input control signal to cause said pallet dolly to move to the extended position and means on said pallet dolly responsive to the deposit of a material-unit thereon and connected with said pallet control means for enabling said power means to move said pallet dolly to the retracted position.
 11. The invention as defined in claim 10 including dimension sensing means adjacent said pallet dolly and connected with said pallet dolly control means, said dimension sensing means being adapted to produce a signal when a selected dimension of a material-unit on said pallet dolly exceeds a predetermined value, said pallet dolly control means being responsive to a signal from said dimension sensing means to cause said power means to hold the pallet dolly in its extended position.
 12. The invention as defined in claim 8 including position sensing means at the load station and connected with said platform control means to energize the platform power means when said material-unit is properly positioned to move the material-unit onto the stacker vehicle.
 13. The invention as defined in claim 8 wherein said positioning means includes a first power actuated positioning member adapted to engage a material-unit at said load station and move it in one direction against a fixed abutment on the load station, a second power actuated positioning member adapted to engage the material-unit and move it in another direction against a second fixed abutment on the load station, position responsive means on the load station and adapted to energize the second power actuated positioning means when the material-unit is positioned against said first fixed abutment.
 14. An automatic storage system for material-units comprising a storage structure with plural sets of bins disposed parallel to each other and having access aisles therebetween, each set of bins comprising multiple bins arranged in columns and rows, a transfer carT including motive power means adapted to move across one end of said aisles to a position adjacent the end of a selected aisle, said transfer cart including motive power control means adapted to energize the motive power means to move the transfer cart to a selected aisle in accordance with an input destination signal for a material-unit, a stacker vehicle disposed in siad selected aisle and adapted to move forward and backward in the aisle and including a platform adapted to support a material-unit and to move laterally in said aisle to transfer a material-unit to or from a selected bin, a said transfer cart including a vehicle station located thereon adapted to receive the stacker vehicle and a load station located thereon so positioned as to permit said stacker vehicle platform to move laterally to transfer a material-unit to and from said load station, said stacker vehicle including driving means for moving along said aisle, control means for said driving means and adapted to position said vehicle selectively with said platform in accurate alignment with a selected bin or with said load station to transfer a material-unit between the load station and the selected bin whereby material-units may be deposited on the mobile load station at one aisle and transported thereby to the selected aisle and transferred from the load station to the stacker vehicle for transport thereby to the destination bin.
 15. The invention as defined in claim 14 including positioning means disposed at said load station adapted to engage a material-unit thereon for positioning it along two axes into accurate alignment with said load station so it will be accurately aligned with said platform.
 16. The invention as defined in claim 15 wherein said load station includes means responsive to the presence of a material-unit on said load station for energizing said positioning means.
 17. The invention as defined in claim 15 wherein said load station comprises a pallet dolly movable from a retracted position at the load station to an extended positon adjacent the load station, said pallet dolly being adapted to receive a material-unit while it is in the extended position and means responsive to said pallet dolly in the retracted position for energizing said positioning means.
 18. The invention as defined in claim 17 including power means connected with said pallet dolly for moving it between said extended position and said retracted position, and pallet dolly control means connected with said power means and being responsive to a manual input control signal to cause said palley dolly to move to the extended position and means on said pallet dolly responsive to the deposit of a material-unit thereon and connected with said palley dolly control means for enabling said power means to move said pallet dolly to the retracted position.
 19. The invention as defined in claim 18 including dimension sensing means adjacent said pallet dolly and connected with said pallet dolly control means, said dimension sensing means being adapted to produce a signal when a selected dimension of a material-unit on said pallet dolly exceeds a predetermined value, said pallet dolly control means being responsive to said signal from said dimension sensing means to cause said power means to hold the pallet dolly in its extended position.
 20. The invention as defined in claim 16 including position sensing means at the load station and connected with said platform control means to energize the platform power means when said material-unit is properly positioned to move the material-unit onto the stacker vehicle.
 21. The invention as defined in claim 16 wherein said positioning means includes a first power actuated positioning member adapted to engage a material-unit at said load station and move it in one direction against a fixed abutment on the load station, a second power actuated positioning member adapted to engage the material-unit and move it in another direction against a second fixed abutment on the load station, position responsive means on the load station and adapted to energize the second power actuated positioning means when the material-unit is positioned against said first fixed abutment.
 22. An automatic storage system as claimed in claim 14 including locking means having a first member mounted on said transfer cart and a plurality of second members each being positioned at a respective one of said aisles adjacent the path of travel of said transfer cart and adapted to coact with said first member, one of said members being movable between an unlocked and a locked position relative to the other member, position responsive means connected with said control means and responsive to the unlocked and locked positions, respectively, of said one member for disabling and enabling, respectively, the energization of said motive power means whereby said transfer cart may be moved from one aisle to another to transfer said stacker vehicle when the locking means are in the unlocked position, and position responsive means operatively connected between said transfer cart and said bin structure for producing a control signal when said stacker vehicle is in alignment with the selected aisle, and actuating means connected with said locking means and responsive to said control signal for moving said one member to said locking position whereby said transfer cart is fixed relative to said bin structure and said stacker vehicle may be removed from and returned to said transfer cart.
 23. The invention as defined in claim 22 wherein the first and second members of said locking means are physically engaged when the said one of said members moves from the unlocked to the locked position said engagement being effective to exert a force on said transfer cart to move it into accurate position relative to said bin structure.
 24. The invention as defined in claim 23 wherein said first member of the locking means is mounted on the transfer cart and comprises a plunger movable transversely of the path of motion of the transfer cart and said second member comprises a striker plate fixed relative to the bin structure, said plunger and striker plate being engageable on a wedge-shaped surface whereby said transfer cart is accurately positioned and locked relative to the bin structure.
 25. The invention as defined in claim 24 wherein said control means comprises an energizing circuit for said motive power means and said position responsive means comprises a position responsive switch in said energizing circuit, said position responsive switch being operatively connected with said plunger and being switched from one condition to another when said plunger is moved between the locked and unlocked positions.
 26. The invention as defined in claim 25 wherein said actuating means comprises a fluid motor connected with said plunger, a reversing valve connected with said motor to move said plunger in the other direction and an electromagnet in said control circuit adapted to be energized by said control signal to actuate said plunger to the locked position when the stacker vehicle is in approximate alignment with the selected aisle. 